Enterocolitis(EC) is the most common and serious postoperative complication of Hirschsprung's disease(HD) with high morbidity and mortality. Probiotics are live microbes that, when administered in adequate amounts, confer health benefit to the host.Based on this previous knowledge on the beneficial effects of probiotics during pro-inflammatory conditions of the gastrointestinal tract, investigators hypothesized that oral probiotics could decrease the incidence and severity of Hirschsprung's disease associated enterocolitis(HAEC).Investigators conducted a prospective, multicenter, randomized and controlled trial to assess whether oral probiotics could decrease the incidence and severity of Hirschsprung's disease associated enterocolitis(HAEC).